Clinically, patients often hold physical examination reports and ask, "doctor, I'm so thin, why do I have severe fatty liver?" It can be seen that many people still have misunderstandings about fatty liver. They take it for granted that fatty liver "is the business of obese people, which has nothing to do with thin people" or that "if you eat vegetarian and diet, you won't suffer from fatty liver". Recently, the Stanford University research team published in the lancet Gastroenterology and Hepatology that 40.8% of patients with fatty liver worldwide are non obese, and even 19.2% are considered "thin". In China, 44.3% of patients with fatty liver belong to this group. Ask How to judge whether you are really thin? Some people look very thin, thin limbs, low weight, and look very healthy. In fact, for fat and thin, we should not only care about body weight. Body mass index (BMI), waist circumference and body fat rate are very important measurement factors. 1. Body mass index (BMI) BMI is an indicator of obesity using height and weight. The recommended BMI classification of Chinese adults is: 18.5-24.9 is normal, 25-29.9 is overweight, and ≥ 30 is obese. The specific calculation method of BMI is: weight (kg) ÷ square of height (m), for example, height of 1.6m and weight of 50kg, and its body mass index is 50 ÷ 1.62 = 19.53. The higher the BMI index, the higher the degree of obesity. BMI should not be measured except for the whole body fat index. 2. Waistline In recent years, more and more evidence shows that systemic obesity judged by BMI can not effectively reflect the distribution of body fat. Waist circumference is the simplest and practical index to measure the degree of fat accumulation in the abdomen (i.e. central obesity). Some people look very thin, but their waist circumference is actually very thick, and the content of visceral fat is not low, so they will also become a high-risk group for fatty liver. The standard of adult central obesity in China is waist circumference: male ≥ 85 cm, female ≥ 80 cm. The more fat accumulated in the abdomen, the higher the fat content in the viscera. 3. Body fat ratio Body fat rate is also very important. Some friends have normal BMI, but the percentage of body fat increases. These people are called human fatty liver. How to calculate the body fat rate? Body fat ratio = (total body fat weight ÷ body weight) × 100%。 The normal range of body fat rate of adults is 20% - 25% for women and 15% - 18% for men. Therefore, we usually pay attention to body fat rate and abdominal circumference in addition to weight. You might as well test yourself according to the actual situation. Second question What are the characteristics of patients with lean fatty liver? The clinical manifestations have the following characteristics: 1. The appearance is not fat, the muscle mass is low, and the body fat content is high. 2. There is internal fat accumulation, such as liver, stomach, pancreas, greater omentum and so on. 3, high levels of blood lipids, high density lipoprotein levels, high risk of fatty liver, diabetes, hypertension and cardiovascular diseases. Therefore, you can't judge whether you have fatty liver by body weight alone. Three questions Is the cause of fatty liver in thin people the same as that in obese people? In addition to fat distribution, the main causes of nonalcoholic fatty liver disease in thin people are as follows: 1. The risk factors of fatty liver in thin people are the same as those in obese people. Eat high sugar, high oil and high-fat diet, such as eating too much takeout, night snacks, cakes and so on. Irregular diet, extra snacks, drinks and cakes, reduced activity, sedentary, reduced skeletal muscle mass, resulting in an increase in the proportion of fat in the body, while the weight gain may not be significant. 2. Genetic susceptibility. Genetic factors have been shown to be associated with obesity and nonalcoholic fatty liver disease. Genetic factors also play an important role in the pathogenesis of thin people. For example, patients with dyslipidemia are more likely to have ectopic fat accumulation, resulting in nonalcoholic fatty liver disease. 3. Especially thin people also have unbalanced nutrition and lack of protein in the body, which affects the synthesis of apolipoprotein by the liver, resulting in the decline of the ability of the liver to transfer fat and the accumulation of fat in the liver. In addition, most thin people like vegetarianism, or have picky eating habits. Long-term vegetarianism or unbalanced diet lead to lack of protein and vitamins in the body and insufficient synthesis of apolipoprotein in the liver, resulting in the weakening of their ability to transport fat outside the liver and the deposition of fat in the liver. On the other hand, long-term vegetarianism leads to the fact that nutrition cannot meet the needs of the body, and excessive secretion of glucocorticoid hormones, resulting in the release of a large number of free fatty acids into the blood and liver. Fatty acids in the liver exceed the transport capacity of liver apolipoproteins and will also deposit in the liver, leading to fatty liver. 4. Intestinal flora disorder. A large number of studies have shown that intestinal bacterial overgrowth, enterogenous endotoxemia and the increased sensitivity of fatty liver to endotoxin are all involved in the occurrence of nonalcoholic fatty liver disease. Four questions Can losing weight also lead to fatty liver? People who lose weight quickly usually go on a crazy diet and exercise. Heat consumption leads to a large decomposition of body fat in a short time, a large increase of harmful substances such as lipid peroxide in the liver, and damage to hepatocytes. Therefore, weight loss can sometimes lead to fatty liver. We must pay attention to scientific and correct methods to lose weight. We can't be eager for quick success and instant benefits and pursue rapid beauty, otherwise the gain will not pay off. Five questions Can a fat liver lose weight? The treatment of fatty liver in lean people is the same as that in obese people. Changing lifestyle is the most effective means. 1. Strengthen exercise and improve muscle content The weight loss of fatty liver in thin people only needs to be reduced by 3% - 5%, so that the waist circumference is reduced and the waist circumference height is higher than normal. By reducing waist circumference, liver fat content can also be reduced to normal, or even completely subsided. However, lean fatty liver has higher requirements for strengthening exercise, because lean fatty liver has less muscle content and more fat content in a sense, so strengthening exercise to improve muscle content may be more meaningful. Jogging, fast walking, cycling and swimming are all good choices, but exercise should reach a certain amount of exercise and stick to it for a long time. You can stick to the same amount of aerobic exercise for half an hour every day, 3-5 times a week. At present, affected by the epidemic, some friends are closed at home. They can choose convenient and simple methods such as rope skipping, aerobics and fast walking in situ. 2. Reasonable diet Three meals a day are fixed and limited, with balanced nutrition. Eat more coarse grains and beans and less white and soft. Supplement high-quality protein, sufficient vegetables and fruits every day, and pay attention to low sugar and low-fat diet. Cook light and less oil, and stay away from fried food. 3. Correct bad habits Drinking less or abstaining from alcohol, sedentary for a long time, liking snacks or overeating, extra meals before going to bed, too little activity and other habits should be corrected and lifestyle adjusted. 4. Careful medication and regular physical examination Many drugs are metabolized through the liver. Improper use of drugs is easy to lead to liver injury, so we should pay attention to rational use of drugs. For people over 40 years of age who have not undergone physical examination, especially those with family history such as obesity, fatty liver and diabetes, regular physical examination should be carried out to achieve early detection and early intervention. (outlook new era)